(a) Technical Field
Embodiments of the present disclosure are directed to a liquid crystal lens and a display device including the same.
(b) Discussion of the Related Art
In general, a display device displays a 2D plane image. Recently, as demand for 3D stereoscopic images has increased in fields such as gaming and movies, a 3D stereoscopic image can be displayed using a display device.
A stereoscopic image display device divides a left-eye image and a right-eye image that have binocular disparity, and respectively provides them to a left eye and a right eye of a viewer. The viewer recognizes the left-eye image and the right-eye image through both eyes, and the images are combined in the brain such that stereoscopicity is perceived.
To create a stereoscopic image, a stereoscopic display device uses linearly polarizing stereoscopic glasses to divide the left-eye image and the right-eye image, however there is an inconvenience in that the glasses must be worn.
To resolve the inconvenience, an autostereoscopic method has been proposed that does not involve wearing glasses. An autostereoscopic method may be one of a lenticular type, a parallax type, an integral photography type, and a holography type, depending on a type of element used to divide the image for each direction, and recently, focus has been on a lenticular type of stereoscopic image display device.
A lens used in the lenticular type may be a convex lens or a Fresnel lens. A Fresnel lens is thinner than a convex lens. A Fresnel lens has a plurality of circular arcs on a surface thereof. The circular arcs of a Fresnel lens refract light.
Recently, a liquid crystal lens has been manufactured that can realize a lens by controlling director distribution of liquid crystals through an electric field. A liquid crystal lens includes an upper substrate, a lower substrate, and a thick liquid crystal layer between the upper substrate and the lower substrate. A liquid crystal lens includes a plurality of electrodes, and each electrode is supplied with a different voltage to control the liquid crystal directors.
In addition, to convert a plane image display method into a stereoscopic image display method, a 2D/3D compatible image display device has been developed, and a lens capable of switching between the 2D/3D image has been developed for this purpose.